davis and f



W. H. DAVIS AND F. E. 1088.

PHONOGRAPH TRANSMISSION.

APPLICATION FILED MAY 9. 1918.

Patented Aug. 12, 1919.

2 SHEETS-SHEET I.

W. H. DAVIS AND F. E. 1038.

PHONOGRAPH TRANSMISSION.

APPLICATION FILED MAY 9. I918.

Patented Aug. 12, 1 919.

2 SHEETSSI'IEET 2.

IN VE N T085 UNITED STATES PATENT OFFICE.

WILLIAM H. DAVIS, OF BRONXVILLE, -AND FREDRICK E. J OSS, OF BROOKLYN, NEW

YORK, ASSIGNOIRS T0 LEKTOPHONE CORPORATION, A CORPORATION OF DELA- WARE.

PHONOGRAPH TRANSMISSION.

Specification of Letters Patent.

Application filed May 9, 1918. Serial No. 233,466.

To aZl Whom it may concern.

Be it known that we, WILLIAM H. DAVIS and. Fiuainuck E. Joss, both citizens of the United States, residing at, respectively, lironxville, county of \Vestchester, State of New York, and Brooklyn, county of Kings, city and State of New York, have invented certain new and useful Improvements in lhonograph Transmission; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention mechanism particularly applicable in connection with sound reproducing or regenerating machines of the type disclosed in U. S. Letters Patent to Marcus C. Hopkins, No. 1,271,527 of July 2, 1918.

An embodiment of the invention is illustrated in the accompanying drawings; but it is to be understood that no limitation to the precise structural details thereof is conte nplated, since the invention is manifestly susceptible of modifications and changes within its legitimate scope, as subsequently claimed, and it is also to be understood that parts of the invention may be used independently of, and separate from, other parts, and in other and different combinations and environments.

In said drawings:

Figure 1 is a vertical sectional view, taken axially of one type of stylus holder, diaphragm and connected parts;

Fig. 2 is an enlarged detail'view, in side elevation, of certain of the parts shown in F ig. 1;

Fig. 3 is an end elevation of Fig. 2;

Fig. 1 is an enlarged, horizontal section taken on the line 4.4 of Fig. 1;

Fig. 5 is a transverse sectional view taken on the line 5-5 of Fig. 4; n

Fig. 6 is a perspective view of the stylus holder and the spring carried thereby, and

Fig. 7 is a detail view similar to Fig. 6, showing the adjusting and clamping block associated with said spring.

The invention is shown as applied to or associated with a Hopkins-type diaphragm l1 and with a transmission rod or interponent 12. The essential feature of this embodiment of the invention is the provision relates to transmission of a spring connection between the transmission member 12 and the stylus holder 21, to effect the resilient support of the latter above suggested. This spring connection will be fully described hereafter, both as to its construction and arrangement and as to its action.

The diaphragm 11, referred to as a Hopkins-type diaphragm, is a sound regenerator of the kind disclosed by Marcus C. Hopkins in his above mentioned U. S. Letters Patent No. 1,271,527, to which reference may be had for a complete description of the said diaphragm. For all present purposes it is sufficient to state that the diaphragm comprises a conical portion of light, vibratile material, which portion, when vibrated from or by a record or other soundvibrated element, is thereby enabled to pro-.

duce self-sustaining sound waves of the same intensity as the original sound waves, so that it takes the place, notonly of the old sound-box, but also of the usual accompanying horn or like amplifier. The diaphragm is rigidly supported at its periphery between a pair of clamping rings 14. and 15, which are fastened together by screws, or in some other suitable manner, and are carried by a spider 16, the hub of the latter being mounted upon one end of a tubular supporting bar 17. This bar is formed with an eccentric bore 18, extending therethrough from end to end and providing a passage through which the vibration-transmission rod or interponent 12 is inserted. The opposite ends of the rod project beyond the bar 17, the rear end of said rod being equipped with a conical cap 19 which engages the apex of the conical portion of the diaphragm. The free or front end of the bar has fitted on it acylindrical cap or sleeve 20, within which are the transmission rod 12 and a portion of the stylus holder 21, the aforesaid end of the rod being here shown as connected to the stylus holder by means of a screw 22,

- accommodated the projecting front end of which passes through a laterallyextending retained in place by means of an adjustable clamping block 26 of semi-cylindrical shape, which is itself secured in position by screws 27, the arrangement of the said Wall of the recess with respect to the supporting bar and the stylus holder being such that the lane of the spring normally coincides Wit 1, or

passes through, the axis of the holder. The

adjustment of the spring afl'ords means for experimentally locating and establishing a particular and very precise resiliency in the exposed length of the spring which serves as a mounting for the stylus holder, and in this Way enables the sensitiveness of the diaphragm to be controlled. It is merely necessary to loosen the hub of the spider 16, thereby freeing the diaphragm to move with the transmission rod, after which the spring is adjusted and the spider hub retightened.

It has been found by actual tests that a construction such as that just described permits the stylus holder to vibrate with marked freedom and yet in true response to the vibrations cut on the phonic lines of the record; that there is an entire absence of pivot-chatter, and of many other usuallypresent disturbing noises; and that said construction enables the stylus holder to transmit its vibrations through the interponent vibrator rod to the regenerating diaphragm in such a way that the latter functions with the maximum efficiency of which it is capable. It will be seen most clearly from Fig. 4 that the stylusholder 21, or said stylus holder in combination with the rod 12 if these two parts be very rigidly interconnected, may be considered a lever having a peculiar pivotal point. Just where this pivotal point is located, for any particular rocking movement of the lever during the time that the stylus is in motion, would be difficultto determine; but obviously such point is always somewhere in the exposed end of the leaf-spring 13 between the planes l3 and 13". In one sense, the pivot point is a variable one, and probably is constantly shifting, according as a vibration of one amplitude is succeeded by a vibration of a different amplitude.

Further description of the invention, its mode of operation, and its advantages is believed to be unnecessary in view of the foregoing, and is, accordingly, omitted. It may be stated, however, that the character of the recording of the sound-waves, i.e.,

whether hill-and-dale or lateral cutting is adopted, is immaterial, and to that extent the showing is to be considered as diagrammatic.

We claim:

1. In a phonograph transmission, the combination, with a supporting bar having a bore extending therethrough; of a diaphragm carried by said bar at its rear end;

a stylus holder at the front end of the bar; a vibration transmission element extending through said bore and connected at opposite ends with said diaphragm and said holder; and a resilient member connecting said holder and the adjacent end of said bar to vibratably support the former.

2. In a phonogra transmission, the combination, with a supporting bar having an eccentric bore extending therethrouglr; of a diaphragm carried by said bar at its rear end; a stylus holder at the front end of the bar; a vibration transmission element extending through said bore and connected at opposite ends with said diaphragm and said holder; and a resilient member connecting said holder and the adjacent end of said bar to vibratably support the former, said member norn'lally occupying a plane which passes through the axis of the holder.

3. In a phonograph transmission, the

combination, with a supporting bar; of a diaphragm carried by said bar at its rear end; a stylus holder at the front end of the bar; a vibration transmission element disposed longitudinally of the bar and connected at opposite ends with said diaphragm and said holder; and a resilient member connecting said holder and the adjacent end of said bar to vibratably mount the former.

4. In a phonograph transmission, the combination, with a supporting bar; of a diaphragm frame adjustable along said bar at one end; a diaphragm mounted in said frame for adjustment therewith; a stylus holder at the other end of the bar; a vibration transmission element disposed longitudinally of the bar and connected at opposite ends with said diaphragm and said holder; and a resilient member connecting said holder and the adjacent end of said bar to vibratably mount the former; said member having an adjustable engagement with said bar to regulate the vibratory movement of the holder.

5. In a phonograph transmission, the combination, with a supporting bar havinga bore extending therethrough; of a diaphragm frame adjustable along said bar at its rear end; a diaphragm mounted in said frame for adjustment therewith; a stylus holder at the front end of the bar; a vibration transmission element extending through said bore and connected at opposite ends with said diaphragm and said holder; and a resilient member connecting said holder and the adjacent end of said bar to vibratably support the former; said member having an adjustable engagement with said bar to regulate the vibratory movement of the holder.

6. Inaphonograph transmission, the combination, with a supporting bar having a recess in its front end; of a diaphragm frame adjustable along said bar at its rear end; a diaphragm mounted in said frame for adjustment therewith; a stylus holder at the front end of the bar; a Vibration transmission element disposed longitudinally of the bar and connected at opposite ends with said diaphragm and said holder; and a resilient member having its body inserted in said recess and its outer end rojecting beyond the bar end and anciiored to the holder to vibratably support the same, said member being adjustably engaged in said recess to vary the effective length and consequent resiliency of its said outer end.

7. In a phonograph transmission, the combination, with a supporting bar having a bore extending therethrough and a recess in its front end; of a diaphragm frame adjustable along said bar at its rear end; a diaphragm mounted in said frame for adjustment therewith; a stylus holder at the front end of the bar; a vibration transmission holder extending through said bore and cess and its outer end projecting beyond thebar end and anchored to the holder to vi-t bratably support the same, said member being adjustably engaged in said recess to vary the effective length and consequent resiliency of its said outer end.

8. The combination of a supportingbar; a vibration transmission element disposed longitudinally thereof; a stylus holder at the front end of the bar having a base provided with a laterally-projecting ear to which the front end of the transmission element is connected; and a resilient member connecting said base and the front end of said bar to vibratably mount the stylus holder.

9. The combination of a supporting'bar;

a vibration transmission element disposed longitudinally thereof; a stylus holder at the front end of the bar having a base provided with a lateral projection to which the front end of the transmission element is connected, the rear face of the base being formed witha slot; and a leaf spring anchored at one end on sai bar and at the other end in said slot to vibratably mount the stylus holder.

WILLIAM H. DAVIS.

FREDRICK E. JOSS. 

